If you receive an offer to publish your book, the first thing to consider is whether it has come from a company that you have submitted to, or has it come from an unsolicited source. Think about how or why you may have been contacted. Perhaps it is because you have been searching publishing companies on the internet and your details have come to this company’s attention.
Even if you have contacted them, consider the details of the contract that you are being offered. Often, a vanity publisher will be a disreputable outfit that offers overpriced, poorly executed, unreliable “vanity” publishing services, and these will be passed off to inexperienced writers as a traditional publishing deal.
That vanity publishers prey on writers who are not experienced in detecting the different types of publishing, is a source of great anger to me. It is not that the writers are foolish they are just not experienced enough to see through deliberately misleading descriptions to recognise a vanity publisher.
The litmus test is this; is the company asking for money? A traditional publisher should be paying the author, not the other way round. On the occasions that I hear someone has been offered a publishing deal, but the author is required to pay a fee to the company, I immediately become very suspicious.
There are other non-traditional publishing houses that openly offer “shared-cost” publishing arrangements. These are where author and publisher share the costs of production, control of the promotion, and income generated by the book on an equal basis. However, these arrangements are always disclosed up front, and these publishers do not try to pass themselves off as traditional publishing houses.